1 files changed, 15 insertions, 31 deletions

diff --git a/kernel/time/jiffies.c b/kernel/time/jiffies.c
index d23b434c2ca7..bc4db9e5ab70 100644
--- a/kernel/time/jiffies.c
+++ b/kernel/time/jiffies.c
@@ -10,28 +10,9 @@
 #include <linux/init.h>
 
 #include "timekeeping.h"
+#include "tick-internal.h"
 
 
-/* Since jiffies uses a simple TICK_NSEC multiplier
- * conversion, the .shift value could be zero. However
- * this would make NTP adjustments impossible as they are
- * in units of 1/2^.shift. Thus we use JIFFIES_SHIFT to
- * shift both the nominator and denominator the same
- * amount, and give ntp adjustments in units of 1/2^8
- *
- * The value 8 is somewhat carefully chosen, as anything
- * larger can result in overflows. TICK_NSEC grows as HZ
- * shrinks, so values greater than 8 overflow 32bits when
- * HZ=100.
- */
-#if HZ < 34
-#define JIFFIES_SHIFT	6
-#elif HZ < 67
-#define JIFFIES_SHIFT	7
-#else
-#define JIFFIES_SHIFT	8
-#endif
-
 static u64 jiffies_read(struct clocksource *cs)
 {
 	return (u64) jiffies;
@@ -44,21 +25,24 @@ static u64 jiffies_read(struct clocksource *cs)
  * the timer interrupt frequency HZ and it suffers
  * inaccuracies caused by missed or lost timer
  * interrupts and the inability for the timer
- * interrupt hardware to accuratly tick at the
+ * interrupt hardware to accurately tick at the
  * requested HZ value. It is also not recommended
  * for "tick-less" systems.
  */
 static struct clocksource clocksource_jiffies = {
-	.name		= "jiffies",
-	.rating		= 1, /* lowest valid rating*/
-	.read		= jiffies_read,
-	.mask		= CLOCKSOURCE_MASK(32),
-	.mult		= TICK_NSEC << JIFFIES_SHIFT, /* details above */
-	.shift		= JIFFIES_SHIFT,
-	.max_cycles	= 10,
+	.name			= "jiffies",
+	.rating			= 1, /* lowest valid rating*/
+	.uncertainty_margin	= 32 * NSEC_PER_MSEC,
+	.read			= jiffies_read,
+	.mask			= CLOCKSOURCE_MASK(32),
+	.mult			= TICK_NSEC << JIFFIES_SHIFT, /* details above */
+	.shift			= JIFFIES_SHIFT,
+	.max_cycles		= 10,
 };
 
-__cacheline_aligned_in_smp DEFINE_SEQLOCK(jiffies_lock);
+__cacheline_aligned_in_smp DEFINE_RAW_SPINLOCK(jiffies_lock);
+__cacheline_aligned_in_smp seqcount_raw_spinlock_t jiffies_seq =
+	SEQCNT_RAW_SPINLOCK_ZERO(jiffies_seq, &jiffies_lock);
 
 #if (BITS_PER_LONG < 64)
 u64 get_jiffies_64(void)
@@ -67,9 +51,9 @@ u64 get_jiffies_64(void)
 	u64 ret;
 
 	do {
-		seq = read_seqbegin(&jiffies_lock);
+		seq = read_seqcount_begin(&jiffies_seq);
 		ret = jiffies_64;
-	} while (read_seqretry(&jiffies_lock, seq));
+	} while (read_seqcount_retry(&jiffies_seq, seq));
 	return ret;
 }
 EXPORT_SYMBOL(get_jiffies_64);